Flipsky watercooled ESC 75200 is not waterproof


Recently I have built an e-foil using Flipsky watersports kit with water-cooled 75200 ESC. Everything was great until I got water leakage in my box. I was thought that 75200 is waterproof but I was wrong. Cable holes are badly sealed, after my e-foil started acting weirdly (not response to the throttle, remote shows empty battery) I have shaked ESC ant water drops came from the cable hole.

This is just FIY. Add extra sealant to the cable holes or put it the sealed box.

It’s stated as IP65 (=not waterproof) on flipsky site so it’s not actually a fault.

Then we can always ask why they do a poor potting if they do it at all…

Before using the ESC, check its tightness. I drilled a small hole near the wall and lightly pumped the pressure inside using a ball inflator

I found that there were bubbles coming out of the hole where the wires came out and added a silicone gasket maker to that area.

After this, bubbles began to come out of the wires, but this is okay, because the connectors will be inside waterproof cases.

Do not inflate too much, otherwise you will ruin the existing seal. Use a hand pump and press very lightly and slowly, just until you see bubbles. Better yet, inflate with your mouth.

Can you share what you are using to seal your ESCs?
Thinking to use lacquer spray for PCB. And when use some potting compound but not sure which to use

It’s soft but not runny. It won’t run into gaps.

Permatex® Ultra Black® RTV Silicone Gasket Maker, 3 OZ - Permatex

You can pour liquid sealant on top, but I didn’t do that, that was enough for me.

I’ve use this silicone as well.
It can be very messy and a bit tricky to work with. I found that using a small syringe (from my children’s medicine cabinet) works well for controlling the flow and placement of the silicone. Easier than squeezing the whole tube.

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This is a gasket silicone, why not use a pourable potting compound? I got some from tme.eu a while ago but now they don’t seem to sell it any longer. MG chemicals have some variants that are sold in small batches, Wacker too.

The problem with these esc is that empty cavities remain there after pouring the compound. They don’t fill them completely. But only from the top. I use the 75200 without water cooling, remove the top cover, cover everything with varnish, and pour everything with a silagerm electronics compound without the top cover. But this is a one-time system! Silagem is very difficult to remove! But so far it’s working, it’s working well.

If you pour that liquid sealant in there, it’s gonna seep into all the electronics and totally flood 'em. And trust me, man, if you ever gotta redo anything, getting that stuff out is gonna be a major pain.

I’ve had more escs die from water than component failure, and the most common component failure has been blown mosfets which hasn’t really been repairable due to the ”blowing up” part

Therefore i’d prefer a fully potted part if the balance is to be done between potting and repair.

Having that said i think the box should be 100% waterproof and the ESC can remain splashproof.

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Good call. But I yanked out all the extra wires in my setup to keep things clean. Might throw some back in later, but for now, I’m all about keeping it light and easy. No need for extra weight if I can keep things lighter.

Magic Gel is great. Waterproof, pourable, and easy to remove…